Solved: the case of the missing moon dust.

The United States attorney's office for eastern Missouri announced Thursday that it had recovered government property stolen more than 40 years ago: a triangular nub of transparent tape an eighth of an inch wide.

Unlike most missing office supplies, this tape was speckled with moon dust brought back by the Apollo 11 astronauts.

"It wasn't much to look at, but I will never be that close to the moon again," Richard G. Callahan, the United States attorney, said in a news release.

The item turned up last month at Regency-Superior, an auction house in St. Louis. The woman who put it up for sale, whose name was not released, told the authorities that her late husband had bought it some years earlier. When she learned of its history, she "immediately and graciously agreed to relinquish it back to the American people," Mr. Callahan's office said.

David M. Kols, president of Regency-Superior, said his auction house knew that selling moon rocks was illegal, but did not realize the prohibition extended to dust. The item was pulled from the auction, and investigators retrieved the tape last Friday. "I've never seen the government move so fast," he said.

Preliminary tests by NASA indicated that bits of the moon were indeed stuck to the tape, although more complete tests will take two to three weeks.

The history of the tape and the dust was never much of a mystery, though. Terry Slezak, who now lives in Boerne, Tex., was a photographer in charge of processing the film brought back from the moon landings. When he opened one of the canisters, dust spilled out and coated his hands.

In a telephone interview Thursday, he said he remembered carefully cleaning the film magazine with towels and tape to prevent the dust from scratching the film. He then hung the tape in his darkroom. Later, presented with a poster board of photographs signed by the Apollo 11 astronauts, "I added the little piece of Scotch tape with the moon dust on it," he said. "I thought that would be kind of neat."

Mr. Slezak said that no one from NASA or law enforcement had ever questioned him about the tape, even when he sold the poster at an auction in 2001.

A German collector of space memorabilia bought the poster -- including the dusty tape, which was about an inch long and was subsequently cut into smaller pieces and sold.

Mr. Slezak was a bit surprised to hear of the legal hubbub. "I haven't seen or heard tell of this thing for a long time," he said.

First Published: June 24, 2011, 4:00 a.m.